docs: clarify gas-prices option (cosmos#19980)

client/flags/flags.go

@@ -126,7 +126,7 @@ func AddTxFlagsToCmd(cmd *cobra.Command) {
 	f.Uint64P(FlagSequence, "s", 0, "The sequence number of the signing account (offline mode only)")
 	f.String(FlagNote, "", "Note to add a description to the transaction (previously --memo)")
 	f.String(FlagFees, "", "Fees to pay along with transaction; eg: 10uatom")
-	f.String(FlagGasPrices, "", "Gas prices in decimal format to determine the transaction fee (e.g. 0.1uatom)")
+	f.String(FlagGasPrices, "", "Determine the transaction fee by multiplying max gas units by gas prices (e.g. 0.1uatom), rounding up to nearest denom unit")
 	f.String(FlagNode, "tcp://localhost:26657", "<host>:<port> to CometBFT rpc interface for this chain")
 	f.Bool(FlagUseLedger, false, "Use a connected Ledger device")
 	f.Float64(FlagGasAdjustment, DefaultGasAdjustment, "adjustment factor to be multiplied against the estimate returned by the tx simulation; if the gas limit is set manually this flag is ignored ")

client/v2/autocli/testdata/help-echo-msg.golden

@@ -15,7 +15,7 @@ Flags:
       --from string              Name or address of private key with which to sign
       --gas string               gas limit to set per-transaction; set to "auto" to calculate sufficient gas automatically. Note: "auto" option doesn't always report accurate results. Set a valid coin value to adjust the result. Can be used instead of "fees". (default 200000)
       --gas-adjustment float     adjustment factor to be multiplied against the estimate returned by the tx simulation; if the gas limit is set manually this flag is ignored  (default 1)
-      --gas-prices string        Gas prices in decimal format to determine the transaction fee (e.g. 0.1uatom)
+      --gas-prices string        Determine the transaction fee by multiplying max gas units by gas prices (e.g. 0.1uatom), rounding up to nearest denom unit
       --generate-only            Build an unsigned transaction and write it to STDOUT (when enabled, the local Keybase only accessed when providing a key name)
   -h, --help                     help for send
       --keyring-backend string   Select keyring's backend (os|file|kwallet|pass|test|memory) (default "os")